JAVA COLLECTION

The Java Collections API's provide Java developers with a set of classes and interfaces that makes it easier to handle collections of objects. In a sense Collection's works a bit like arrays, except their size can change dynamically, and they have more advanced behaviour than arrays.

Most of the Java collections are located in the java.util package. Java also has a set of concurrent collections in the java.util.concurrent package

Java Collections
Java Collections Introduction Overview of Interfaces     Iterable    Collection     Generic Collections         List    Set SortedSet    NavigableSet    Map    SortedMap NavigableMap     Queue     Deque    Stack         hashCode() and equals()     Sorting